Well, as I'm sure you already know, the Connect:Direct Process language has a very limited set of instructions (i.e. COPY, RUN JOB, and RUN TASK being the major ones). RUN JOB doesn't take any parameters. RUN TASK does.

So, I'm guessing that in this case only the RUN TASK would make sense. What you'd call to be executed I don't know, since it would have to check for the existence of the dataset (presumably using LISTCAT) and then someone returning that information back to the PNODE (maybe as a return-code value).